系列膜超滤处理在茶多糖分离纯化中的应用研究

Study on the isolation and purifcation of tea polysaccharides with systematic membrane ultrafiltration

炒青绿茶经水提取后,茶汤用0.2μm孔径的膜过滤,滤液依次经过150k、20k、6ku的膜组件进行分级和浓缩,分别对各部分截留液和滤过液中的总糖、多糖、糖醛酸、蛋白质、茶多酚、咖啡碱等化学成分进行含量分析。结果表明,茶汤中50%以上的干物质能够透过20ku的膜,对于多糖来说,则以20ku膜截留液中含量最高,其占干物质的比重可达到36.86%,150ku膜和6ku膜截留部分中多糖含量分别为27.13%和21.16%,而透过6ku膜部分中占干物的含量则仅为1.09%,由此可见,膜分离处理对于茶多糖的分离纯化效果明显;相关的蛋白质、茶多酚、咖啡碱等化学成分的分析结果,亦说明了膜技术在茶汤中化学成分分离中的应用效果。

A series of ultrafiltration membrane of 0.2μm, 150k, 20ku, and 6ku, were applied to separate and purify tea polysaccharide. The contents of polysaccharide, uronic acid, protein, polyphenol, caffeine, and amino acids were determined. Results showed that one half of dry matter could get through the 20k u membrane. As for the content of olysaccharide in all these proportions, the proportion of between 20ku and 150 k u was the highest with 36.86% polysaccharide, above 150k u and above 6k u were 27.13% and 21.16% individually, and below 6k u was only 1.09%. Results of uronic acid, protein, polyphenol, amino acids and caffeine also showed that membrane technology could be used to separate and purify polysaccharide and other compounds in tea.